Aging of alcoholic beverages using controlled mechanically induced cavitation

ABSTRACT

An extreme acceleration of the process of aging spirits to obtain aged liquors includes circulating the spirits through a cavitation zone within a controlled cavitation reactor and exposing the spirits therein to high energy cavitation induced shockwaves. Sources of flavor and color such as charred wood chips may be added to the spirits to provide the color and flavor of liquors aged for years in traditional charred oak barrels. The method and apparatus of the present invention obtains the same conversion of undesirable alcohols, flavor extraction, and color as years of aging in an oak barrel but does so in a matter of minutes or hours. The apparatus and method also can be used in conjunction with traditional aging techniques and methods and the total aging time is still reduced dramatically.

REFERENCE TO RELATED APPLICATION

This is a continuation of U.S. patent application Ser. No. 15/085,616filed on Mar. 30, 2016, which claims priority to the filing date of U.S.provisional patent application 62/141,595 filed on Apr. 1, 2015 and tothe filing date of U.S. provisional patent application 62/293,069 filedon Feb. 9, 2016. The contents of these patent applications are herebyincorporated by reference.

TECHNICAL FIELD

This disclosure relates generally to the aging of alcoholic beveragessuch as distilled spirits, beer, and wine, and more specifically to therapid aging of alcoholic beverages using controlled mechanically inducedcavitation to enhance maturity and drinkability of resulting beveragesthereby simulating traditional aging.

BACKGROUND

The most desired of spirits are aged. Examples include whisky, scotch,bourbon, tequila, and many others. Likewise, beer and wine also are agedprior to drinking. These aged products are more expensive by virtue ofthe time and resources expended during the aging process and arguablyhave more enjoyable flavors and aromas than alcoholic beverages that arenon-aged. The aging process softens the ‘burn’ of the ethanol whilesmoothing out flavors and adding even more pleasant ones. Further,undesirable and even poisonous alcohols and other products are largelyconverted to more desirable and less offensive tasting esters duringaging.

Traditionally, newly distilled spirits are aged in a variety of ways,with perhaps the most common being barrel aging. Newly distilled or“white” whisky, for example, is commonly aged in Southern white oakbarrels that have been burnt or charred on the inside. Aging exposes thealcohol and other compounds both to oxygen in the air and the storagematerials themselves (charred oak for instance) for long periods oftime, usually many years or even decades. This alters the chemicalstructure of many of the alcoholic compounds and changes the color,aroma, and flavor of the resulting liquor in various and mostlybeneficial ways. Beer and wine also are aged in aging vessels forsimilar reasons.

Alcoholic beverages are created through fermentation of a biologicalproduct, be it grapes, grain mash, fruit, plants, or another product. Inthe case of distilled spirits, distillation yields primarily ethanol,but also produces aldehydes, esters, and fatty acids, all of which havevery specific flavors and aromas. It is at least in part the uniquecombination of these chemicals that make spirits different from oneanother. Multiple distillations and filtering can remove many of thesecompounds to create a “clean” or aromaless and flavorless spirit such asVodka. The choice of raw materials, the fermentation process, and thedistillation technique and equipment will all contribute to the overallchemical composition and therefore the aroma and taste of the finalproduct.

Distilling alcohol creates beneficial byproducts, as mentioned above,but also creates bad-tasting and poisonous byproducts, including butane,methanol, hydrazines, acetates, and acetaldehydes. Both good and badbyproducts often are grouped together under the label “congeners.”Fortunately, the good congeners happen to be quite stable, whereas thebad ones break down or are converted to more desirable compounds or atleast to inert compounds over time. Aging a distilled product allowsthis time to pass, thereby decreasing the amount of bad tastes andpoisons and increasing the amount of good flavor and aroma. Research hasshown that basically all the effects of aging occur within fifteen yearswith virtually no perceptible change in aroma and flavor occurringthereafter. This is part of the reason why, for instance, most scotch isaged for between 12 and 15 years.

There have been attempts over the years to obtain the beneficialchemical changes in distilled spirits caused by aging without having towait for years for them to occur. Some distillers, for example, preferto age spirits in small barrels, which increases the relative area ofcontact between the spirits and the inside of the barrel. This has notbeen completely successful however and still can require several yearsto obtain desired benefits. More recently, so-called artificiallyaccelerated aging has become known and has been tried. In one suchprocess, a distilled spirit is pumped through an oxygenated chamber,where it is subjected to high-intensity ultrasonic energy or soundwaves. The agitation caused by the sound waves induces esterification.It has been shown that this process can at least to some extentartificially replicate the aging process of liquor such as whisky byinducing more harsh “higher” alcohols like isopropanol to react withfatty acids to produce esters with more pleasant flavors. This is oftenreferred to “oxidation” in the industry. While it is claimed thatultrasound aging can reduce the production of aged liquors from years tohours, the result has not been completely satisfactory at least in partbecause it has proven very challenging to scale up ultrasound processesto commercial production volumes.

A need exists for a method and apparatus that can obtain the samebeneficial chemical reactions and infusion of flavors in alcoholicbeverages such as distilled spirits, beer, and wine caused bytraditional aging, but obtains them in hours rather than years. Themethod should be able to age alcoholic beverages in a continuous processand in commercial volumes. It is to the provision of such a method andan apparatus for carrying out the method that the present invention isprimarily directed.

SUMMARY

Briefly described, a method and apparatus is disclosed for aging analcoholic beverage such as distilled spirits, beer, or wine (which maycollectively be referred to herein as “spirits”) in hours rather thanyears. The process can be used to age spirits in commercial volumes andin such a way that the final product is virtually indistinguishable fromspirits aged for years in barrels or other aging vessels. The methodincludes passing liquid spirits through a treatment zone and inducing inthe liquid highly energetic cavitation events. Preferably, the liquid ispassed through a controlled cavitation reactor such as that disclosed inU.S. Pat. Nos. 8,465,642; 8,430,968; 7,507,014; 7,360,755; and6,627,784, each of which is hereby incorporated by reference in itsentirety. The reactor has a closed cylindrical housing within which acylindrical rotor is rotatably mounted. The treatment zone is definedbetween the outer surface of the rotor and the inner surface of thehousing. Bores are formed through the outer surface of the rotor andwhen the rotor is rotated at a high rate with spirits in the treatmentzone, very energetic cavitation events are generated within the bores.

The cavitation events within the bores in turn generate micro shockwaves that propagate through the spirits in the treatment zone. Theshock waves, which are very highly energetic, break down undesirablealcohols, tannins, and other chemicals in the spirits just astraditional aging does, thus mellowing the taste of the spirits. In oneexemplary embodiment, charred wood chips are mixed with distilledspirits and the cavitation events draw out the flavors from the woodchips and infuse them in the distilled spirits. The result is liquorcomparable in color, aroma, and taste to that obtained from years ofaging in a barrel, but requiring minutes or hours rather than years toobtain. In another embodiment, hops are added to beer and the shockwaves draw out the flavor of the hops and infuse the flavor in the beermore efficiently than traditional aging.

With the proliferation of craft breweries and their more heavily hoppedbeers, the demand for hops and their prices have increased. Typicallyonly about one third of the flavor potential is extracted from hopsduring traditional beer aging. Hops can be added for bittering purposesprior to fermentation or for flavor purposes post fermentation, oftencalled dry hopping. Using the pressure fluctuations of shock waves fromcavitation, hop flavor can be extracted and infused into beer much moreefficiently in a very short time. This is accomplished in a relativelylow shear environment to minimize protein damage to the hops and tominimize fines production. The ultimate result is a reduction in hopsusage to produce a desired hops flavor in beer as well as higher yieldsdue to more efficient flavor extraction and less beer soaked hop waste.Other flavorings such as coffee or chocolate also can be added.

Red “young wines” often have a strong tannin taste. Reduction of tanninscommonly requires aging of wine in barrels or stainless steel agingvessels for many years. This reduces the tannins and leads to improvedtaste and thus increased value. This tannin reduction is a chemicalreaction and it has been found that this chemical reaction can be spedup greatly by passing young wine through a controlled cavitation reactoraccording to the present invention. Accordingly, the present inventioncan be applied to wine, with or without added flavorings, to reduce oreliminate the traditional aging process.

These and other aspects, features, and advantages of the presentinvention will be better appreciated upon review of the detaileddescription set forth below taken in conjunction with the accompanyingdrawing figures, which are briefly described as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing one embodiment of an apparatus forcarrying out the method of the present invention.

FIG. 2 is a schematic view showing another embodiment of the inventionused here in conjunction with traditional pre-aging.

FIG. 3 is a schematic view showing yet another embodiment of theinvention used here in conjunction with traditional post-aging.

DETAILED DESCRIPTION

The invention will now be described in more detail and this descriptionshould be reviewed in conjunction with the accompanying drawing figuresfor enhanced clarity. Mechanically induced and controlled cavitationsuch as that produced by the controlled cavitation devices disclosed inthe incorporated references, is used according to the present inventionto obtain artificial aging of alcoholic beverages such as distilledspirits on a high volume commercial scale. In one embodiment, the systemincludes a reservoir tank for holding an alcoholic beverage during theaging process. A pump circulates the beverage from the reservoir tank,through the controlled cavitation device, and back to the reservoirtank. In this way, the alcoholic beverage being aged can be circulatedthrough the controlled cavitation device for as many cycles as necessaryto obtain the desired degree of aging and flavoring.

In another embodiment, charred wood chips are added to distilled spiritsand become entrained in the flow through the controlled cavitationdevice. The intense cavitation to which the spirits and wood chips aresubjected in the cavitation device penetrate the wood chips and extractscolor and flavor from them, which is infused into the liquid. Thisprocess also drives the liquid spirits into and out of the pores of thechips, which helps filter some undesirable compounds from the mix inmuch the same way that the charred interior of an oak barrel does overyears of traditional aging. In other embodiments, hops and/or otherflavors may be added to the alcoholic beverage for the aging of beersfor example. Other flavoring and/or aroma sources such as fruits, oils,chocolates, flowers, spices, and other substances may be added for theproduction of a variety of products from flavored liquors to beer towine and even to perfumes.

When used to age distilled spirits, the system of this invention can runfor varying periods of time to obtain numerous cycles of a mixturethrough the controlled cavitation device. Varying amounts of char andvarious species of wood chips and/or flavoring may be selected to obtaina desired flavor, color, and filtration effect. It has been found thatthe time required for aging can range from a few minutes to many hoursdepending upon the composition of the original distilled spirit, theamount of desired color and flavor desired, and the number of years oftraditional aging being matched. A heat exchanger may also beincorporated in the loop for longer runs to dissipate heat build-upcaused by the cavitation device and any exothermic reactions occurringin the mix.

Internal clearances within the controlled cavitation device such as thespace between the rotor and interior walls of the housing may beadjusted to accommodate different size charred wood chips. This isadvantageous since wood chip surface area is an independent variable inthe resultant aging process. Wood chips may also be substituted with areplaceable wooden ring insert that is internally concentric to thecontrolled cavitation device housing. Such a ring can be charred priorto an aging process to obtain the same desirable characteristics as thecharred interior walls of a traditional oak barrel. In either event, thespirits are forced into and out of the pores of the charred wood chipsor charred ring by the high intensity shock wave induced pressurevariations, thereby releasing color and flavor into the mix. The intensepressure fluctuation also functions to remove sulfur species and othercontaminants from distilled spirits through a filtration process akin tocharcoal filtration. More specifically, the spirits are forced by thepressure variations into and out of the pores and particles of thecharred wood, which filters the spirits in much the same way as anactivated charcoal filter bed. Advantageously, the flavoring, coloring,and filtering process are accelerated by orders of magnitude overtraditional barrel aging processes.

As mentioned above, ultrasound has been used in the past to obtainsomewhat accelerated aging of spirits. The system of the presentinvention has many advantages over ultrasound treatment. For instance,ultrasound aging systems can work acceptably well on a small orlaboratory scale, but such systems are difficult to scale up andreplicate laboratory results in commercial volumes. The use ofcontrolled cavitation in the present invention provides similar or nearidentical results at nearly any commercial volume. Cavitation events inthe controlled cavitation device typically produce intense shock wavesin a liquid being treated that expose the molecules in the liquid to farhigher energies than are possible with ultrasound. This can result inmore rapid flavor intensification and more rapid conversion ofundesirable alcohols in the mixture into esters and other lessobjectionable compounds.

Gasses such as oxygen also may be added to the mix to accelerate theoxidation and conversion of undesirable alcohols and other chemicals.Also, ultrasound liquor aging devices rely on small clearances andmechanical shear to enhance the effects of the ultrasound aging process.These requirements are not conducive to particulates like wood chipsbeing added to the liquor mix. A controlled cavitation device of thepresent invention can easily accommodate wood chips and other solidsbecause of its inherent low shear and relatively large internalclearances.

The same principles used to extract flavor and color from charred woodchips in liquor aging can be used to extract sugars, starches, oils, andother substances from woods and other lignocellulosic material inapplications such as ethanol and biogas production. Substances such aswaste food or algae can experience component extraction in a similarway. In such processes, the intense pressure fluctuations caused by thecavitation induced shock waves force a solvent into a solid to removeentrapped components such as sugars and starches. These intense highenergy shock waves are also capable of causing lysis of pressurizedbodies like cells. Examples of this include treatment of algae orbacteria with the cavitation induced lysis allowing for oil andcarbohydrate extraction or pasteurization. Cavitation can also reversehornification where the pore structure of a lignocellulosic materialdries and bonds to itself limiting future use of its natural capillarysystem. The pressure fluctuations can force solvent into this structureand reopen it to near its original condition prior to drying.

FIG. 1 illustrates in simplified schematic form a controlled cavitationreactor suitable for use in carrying out the methodology of the presentinvention. Such a reactor is described in detail in the incorporatedreferences, and so will be describe only generally here. The reactor 11comprises a reservoir tank 12 for holding a liquid alcoholic beverageduring the aging process. Liquid is drawn from the reservoir tank 12through conduit 13 by a pump 14 and delivered through a flow meter 16and conduit 17 to a controlled cavitation reactor 18. The controlledcavitation reactor 18 generally comprises a cylindrical housing havingan internally mounted cylindrical rotor. A space is defined between theouter peripheral surface of the rotor and the inner peripheral surfaceof the housing and this space is referred to as the cavitation zone.Cavitation-inducing structures such as radial bores are formed in or onethe outer peripheral surface of the rotor. The rotor is rotated withinthe housing by an electric motor 19.

The liquid is pumped through the cavitation reactor within which itflows through the cavitation zone. As the rotor is rotated at a highrate, continuous cavitation events are induced in the liquid within theradial bores. This, in turn, produces highly energetic shock wavescaused by continuously collapsing cavitation bubbles to propagatethrough the liquid in the cavitation zone. These shock waves induce thereactions described above within the alcoholic beverage, therebyduplicating traditional aging processes, but doing so in minutes ratherthan years. Charred wood chips may be mixed with the liquid,particularly when aging distilled spirits, to infuse the white spiritswith color and flavor similar to that resulting from years of aging incharred barrels. After treatment in the reactor 18, the liquid flowsthrough conduit 21 and may flow through a heat exchanger 22 to removeunwanted heat induced by the energy of cavitation. The cooled liquidthen flows through conduit 23 and inlet 26 back to the reservoir tank12. The liquid and entrained chips and/or other flavorings if desiredmay be circulated through the cavitation reactor as many times asdesired to obtain a desired level of aging, flavor, and aroma. Then, itcan be extracted as an aged and flavored alcoholic beverage, asindicated by arrow 28.

FIGS. 2 and 3 illustrate hybrid systems for aging distilled spirits thatinclude artificial aging with high energy cavitation in conjunction withtraditional aging. Of course, such a hybrid system can be used in theaging of beer and wine in the same way. In FIG. 2, distilled spirits arepartially aged in a traditional manner such as being left in a charredoak barrel 27 for a specified period of time. This time preferably isfar less than the years required for full barrel aging and results inpartial aging, partial filtration, and partial infusion of the desiredflavors of the charred oak into the distilled spirits. The partiallyaged spirits can then be subjected to the cavitation induced aging inthe apparatus described above for one or more cycles. Charred wood chipsand/or other flavorings can be introduced if desired to obtainadditional flavoring, coloring, and filtration during the process. Theresult is a fully aged liquor having characteristics unique to thecharred oak barrel in which it was partially aged, but also having thefull robust aging that traditionally only results from years ofresidence in oak barrels. Again, the total time to obtain the fully agedliquor product is a fraction of the time required to obtain the samebenefits with traditional aging.

FIG. 3 illustrates an alternate hybrid process for obtaining similarresults. Here, freshly distilled spirits are delivered from thedistiller directly to a controlled cavitation device 11 according to theinvention. As described above, the spirits are circulated through thecontrolled cavitation reactor or cavitator for a predetermined number ofcycles, with or without the addition of charred wood chips and otherflavoring and filtering media. After treatment for minutes or hours inthe cavitation reactor, the distilled spirits are partially aged as ifthey had resided in traditional charred oak barrels for months or evenyears. The partially aged spirits may then be delivered to traditionalcharred oak barrels or other aging vessels for further aging in a moretraditional manner. This may be desired, for instance, to infuse theresulting liquor with unique flavors from the barrel or for otherreasons. After traditional aging in the barrel for a time far less thanthe several years usually required, the liquor is fully aged andvirtually indistinguishable from its more venerable predecessors. Again,the total time to obtain the desirable flavor and character of liquoraged for years is reduced to a fraction of that time using a combinationof the methodology of the present invention and traditional agingtechniques.

The invention has been described herein in terms and within the contextof exemplary embodiments and methodologies considered by the inventorsto represent the best modes of carrying out the invention. However, theillustrated embodiments are not intended to and should not be construedto limit the scope of the invention. For example, while aging distilledspirits has been used in some instances as an example of the use of thisinvention, the invention itself is much broader than this. For instance,the methodology of the invention has been found useful in beermanufacturing, where pumping beer through a controlled cavitationreactor with hops and other flavorings can simulate the aging process ina fraction of the time. Wine can also be aged using the methodology ofthis invention. When aging wine, the wine may be pumped through acontrolled cavitation reactor with wood chips and/or other flavorings.Exposure to shock waves in the cavitation zone accelerates many of thechemical reactions that naturally occur slowly with traditional beer andwine aging. Thus, the term “spirits” as used herein is meant to beconstrued to encompass beer and wine as well as distilled spirits.

Any desired flavoring can be included in a stream of spirits, beer, orwine being aged including those mentioned and, for instance, coffee andchocolate (sometimes used to flavor beer) an any other flavoringdesired. It will be appreciated by the skilled artisan, therefore, thata wide gamut of additions, deletions, and modifications, both subtle andgross, may be made to the example embodiments without departing from thespirit and scope of the invention exemplified by such embodiments.

What is claimed is:
 1. A method of aging an alcoholic beverage toproduce an aged beverage, the method comprising the steps of: (a)obtaining a volume of alcoholic beverage to be aged; and (b) subjectingthe alcoholic beverage to cavitation within a cavitation zone of acontrolled cavitation reactor.
 2. The method of claim 1 wherein step (b)comprises circulating the alcoholic beverage through the cavitation zonetwo or more times.
 3. The method of claim 1 further comprising the stepof introducing additives to the alcoholic beverage prior to step (b). 4.The method of claim 3 wherein the additives comprise wood chips.
 5. Themethod of claim 4 further comprising charring the wood chips prior tointroducing them to the distilled spirits.
 6. The method of claim 3wherein the additives comprise flavorings.
 7. The method of claim 1further comprising the step of at least partially aging the alcoholicbeverage in a vessel prior to step (b).
 8. The method of claim 7 whereinthe vessel comprises a charred barrel.
 9. The method of claim 1 furthercomprising the step of at least partially aging the alcoholic beveragein a vessel following step (b).
 10. The method of claim 9 wherein thevessel comprises a charred barrel.
 11. The method of claim 1 furthercomprising the step following step (b) of cooling the alcoholic beveragein a heat exchanger.
 12. The method of claim 1 wherein the alcoholicbeverage comprises distilled spirits.
 13. The method of claim 1 whereinthe alcoholic beverage comprises beer.
 14. The method of claim 13further comprising adding hops to the beer prior to step (b).
 15. Themethod of claim 1 wherein the alcoholic beverage comprises wine.
 16. Amethod of aging an alcoholic beverage to produce an aged alcoholicbeverage, the method comprising the steps of: (a) collecting thealcoholic beverage in a reservoir tank; (b) pumping the alcoholicbeverage from the reservoir tank to a controlled cavitation reactorhaving a cavitation zone; (c) passing the alcoholic beverage through thecavitation zone of the controlled cavitation reactor to break downundesirable components in the alcoholic beverage normally broken down bytime in an aging vessel to produce an aged alcoholic beverage; (d)moving the aged alcoholic beverage back to the reservoir tank; and (e)optionally repeating steps (b) through (d) to expose the aged alcoholicbeverage to cavitation within the cavitation zone a predetermined numberof times to age the alcoholic beverage further; and (f) collecting theaged alcoholic beverage.
 17. The method of claim 16 further comprisingthe step of introducing additives into the alcoholic beverage prior tostep (c).
 18. The method of claim 17 wherein the additives comprise woodchips.
 19. The method of claim 18 further comprising the step ofcharring the wood chips prior to introducing them into the alcoholicbeverage.
 20. The method of claim 16 further comprising the step priorto step (a) of partially aging the alcoholic beverage in an agingvessel.
 21. The method of claim 20 wherein the aging vessel comprises acharred wood barrel.
 22. The method of claim 12 further comprising thestep following step (f) of storing the collected aged alcoholic beveragein an aging vessel for a predetermined period of time.
 23. The method ofclaim 22 wherein the aging vessel comprises a charred wooden barrel. 24.The method of claim 16 wherein the alcoholic beverage comprises adistilled spirit, beer, or wine.